A group that works to help control wormer resistance in sheep has urged UK vets, advisers and farmers to integrate 4-AD (monepantel) and 5-SI (derquantal) wormer classes into worm control programmes.

This is because SCOPS (Sustainable Control of Parasites in Sheep) – a group spearheaded by well-known sheep consultant Lesley Stubbings – is aware of a report of resistance of sheep nematodes to monepantel anthelmintics in the Netherlands.

The full details are not yet available, said SCOPS, but the group understands this situation has arisen because the farms have relied on the 4-AD product as a result of having resistance to all other classes available to them.

Peter Baber, SCOPS chairman and sheep farmer, said the news comes as a timely warning to the UK.

“This is exactly the situation SCOPS predicted would occur if we do not integrate the new groups into worm control strategies before the older products become ineffective,” he said.

“There are still a large number of UK farms where one or more of the three older groups remain effective. If we carefully integrate the 4-AD and 5-SI products into worm control programmes now, it will extend the useful life of all groups.

“The Dutch example serves to illustrate the folly of us leaving them until they are the only option.”